April is Liar’s Month in the NFL, but I’m not paid by The League, so I can be straight.

If the Chargers use their 18th overall pick in next week’s draft on a guard — or any athlete of the offensive persuasion — then their entire football staff should be taken by ambulance to the Betty Ford Clinic on Dean Spanos’ dime.

I do not believe it will happen. If it happens I won’t believe it.

I’ve read some of the 15 million mock drafts, 15 million put together on pure guesswork after the first couple of picks. Quarterbacks Andrew Luck and Robert Griffin III will go 1-2 overall to Indianapolis and Washington, followed by a mad scrum. Even Colts owner Jim Irsay has left some doubt as to whether he’ll take Luck No. 1. He’s playing with those willing to be played.

I’ve read reports from our young whippersnapper Chargers beat man Michael Gehlken, who had a nice piece Monday on how the Chargers might be interested in Stanford guard David DeCastro if he’s still around at 18 (which he most likely will be, in that he’s a guard).

Well, being a person of interest in April doesn’t mean squat. People talk about grabbing the best player available vs. need. That could be the case with the Chargers, who once could gamble on draft day — when they had more players. But I can’t help but doubt the best player available is going to be a guard.

Not that guards aren’t important. But the Chargers already have two starting guards in Louis Vasquez and Tyronne Green and if they want a backup they don’t have to rip out their throats to get one in the first round. DeCastro is a nice player. He could be in the NFL for 15 years. The Chargers don’t need him.

For the first time in 60 years, one team, the Saints, had two guards — Carl Nicks and Jahri Evans — make AP All-Pro first team. Nicks was a fifth-round pick in 2008 and Evans a fourth-rounder in 2006. Kris Dielman, the Chargers’ Pro Bowl guard forced to retire with concussion issues, wasn’t drafted and wasn’t even an offensive lineman when he got to San Diego.

Translation: You can find guards. Maybe not John Hannah, but DeCastro isn’t John Hannah.

Yet you’ll see many mocks out there that have the Chargers taking DeCastro. I wonder why. Has a little bird been spreading the rumor? It’s April, time for liar’s poker. These things happen. It’s commonplace for a team to leak information — false or true — about a player in hopes he may slip to them.

The classic was Dan Marino. When he came out of Pitt in 1983, there was talk he had a drug problem (which he didn’t), that he wasn’t football smart (which he was) and that he was injury-prone (which he wasn’t). So one of the great passers in the history of the planet slipped to Miami (27th overall) at the end of the first round. Any skulduggery afoot? Five quarterbacks went in front of Marino.

Bobby Beathard, then Washington’s general manager, had the last (28th) pick in the first round that year, and as smart as he was, he wouldn’t deal with Marino. “I had him rated higher than I’d ever rated a player,” Beathard told me one day during his time as Chargers GM, “higher than John Elway (who went No. 1 overall in 1983). But if Marino had been on the board when we drafted, I still wouldn’t have taken him.”

Remember, the Chargers had three No. 1s in 1983, and took Billy Ray Smith, Gary Anderson and Gill Byrd — all before Marino, who would have been ideal to come in and study under Dan Fouts. Everyone was bamboozled. Did Miami fan the lies? If the Dolphins did, good for them, because they got a Hall of Fame quarterback.

This year we have more leakage, that LSU cornerback Morris Claiborne scored 4 out of 50 on his Wonderlic test. Now I don’t know exactly what good the leak does, in that all NFL teams have access to scores, but when this sort of thing is made public it possibly can plant a seed of doubt — not only within the franchise, but the fans.

Claiborne is going to be drafted very high. He’s terrific. The leak was stupid and an outrage. The young man has a learning disability.

Another who has slipped badly due to attitude is Arizona State linebacker Vontaze Burfect. He could be a star. Someone will draft him, maybe a team spreading doubts.

So when I hear the Chargers could be taking a guard, I’m not buying what’s being sold. General Manager A.J. Smith, who needs a strong safety and a pass rusher, has signed 16 free agents this spring, all but four of them offensive players.